The famous Ring Nebula (also catalogued as Messier 57, M57 or NGC 6720) appears in the northern constellation of Lyra. It is a prominent example of a planetary nebula. This is a shell of ionized gas expelled into the surrounding interstellar medium by a red giant star, which was passing through the last stage in its evolution before becoming a white dwarf.
Read more about Ring Nebula: History, Observation, Properties
Famous quotes containing the word ring:
“It is engend’red in the eyes,
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In the cradle where it lies.
Let us all ring fancy’s knell.
I’ll begin it—Ding, dong, bell.”
—William Shakespeare (1564–1616)